If someone is trying to save money on Nitrox fills maybe CCR is not the way to go?You have lots diving experience, you have some of the gear, you have great wrecks like the Stolt that are fun with more bottom time. It seems like you are a good candidate to actually do the deco training and do this the right way. Why mess around with a non-standard and potentially dangerous approaches when you can get some training that will really open up your diving?
I didn't get tech trained to do very deep wrecks, I just wanted to be able to spend more time at moderate depths.
And if you REALLY like the idea of doing the top part of the wreck on a richer mix than the bottom to stretch out those NDLs, maybe constant PO2 is for you... Why settle for just two mixes when you can have a machine that will give you whatever you want?
With rec diving there are only 2 failure modes for the reg in your mouth: you can breathe or you can’t. The troubleshooting flow chart is simple and you know immediately if you are in trouble.
With tech diving you add the failure mode of being able to breathe but not necessarily having a life supporting gas, but as long as you haven’t changed regs then if you were good you should still be good.
CCR adds the failure mode of not having a breathable gas even though you have not changed anything (one breath from death etc)
I would respectfully submit that the OP is not really in a mindspace to safely use a breather, yet.
WRT the question of a slung bottle, that would make it easier to avoid a hot switch but as long as there is a reg on you that will kill you, it’s going to be waiting for just that. Training is needed to mitigate the risk.
There’s nothing down there worth dying for.